System and method for user-specified pronunciation of words for speech synthesis and recognition

ABSTRACT

The method is performed at an electronic device with one or more processors and memory storing one or more programs for execution by the one or more processors. A first speech input including at least one word is received. A first phonetic representation of the at least one word is determined, the first phonetic representation comprising a first set of phonemes selected from a speech recognition phonetic alphabet. The first set of phonemes is mapped to a second set of phonemes to generate a second phonetic representation, where the second set of phonemes is selected from a speech synthesis phonetic alphabet. The second phonetic representation is stored in association with a text string corresponding to the at least one word.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. Provisional Ser. No.61/832,753, filed on Jun. 7, 2013, entitled SYSTEM AND METHOD FORUSER-SPECIFIED PRONUNCIATION OF WORDS FOR SPEECH SYNTHESIS ANDRECOGNITION, which is hereby incorporated by reference in its entiretyfor all purposes.

TECHNICAL FIELD

The disclosed implementations relate generally to digital assistants,and more specifically, to digital assistants that make use ofuser-specified pronunciations of words for speech synthesis andrecognition.

BACKGROUND

Just like human personal assistants, digital assistants or virtualassistants can perform requested tasks and provide requested advice,information, or services. An assistant's ability to fulfill a user'srequest is dependent on the assistant's correct comprehension of therequest or instructions. Recent advances in natural language processinghave enabled users to interact with digital assistants using naturallanguage, in spoken or textual forms, rather than employing aconventional user interface (e.g., menus or programmed commands). Suchdigital assistants can interpret the user's input to infer the user'sintent, translate the inferred intent into actionable tasks andparameters, execute operations or deploy services to perform the tasks,and produce outputs that are intelligible to the user. Ideally, theoutputs produced by a digital assistant should fulfill the user's intentexpressed during the natural language interaction between the user andthe digital assistant.

Digital assistants that interact with users via speech inputs andoutputs typically employ speech-to-text processing techniques to convertspeech inputs to textual forms that can be further processed, and speechsynthesis techniques to convert textual outputs to speech. In bothcases, accurate conversion between speech and text is important to theusefulness of the digital assistant. For example, if the words in aspeech input are incorrectly identified by a speech-to-text process, thedigital assistant may not be able to properly infer the user's intent,or may provide incorrect or unhelpful responses. On the other hand, ifthe words in a speech output are incorrectly pronounced by the digitalassistant, the user may have difficulty understanding the digitalassistant. Moreover, incorrect pronunciations by the digital assistantmake the assistant seem less polished and less capable, and may reduceusers' interest and confidence in the digital assistant.

For many words, accurate recognition and synthesis are relatively easy,because their pronunciations are fairly standard, at least betweenpeople with similar accents or from similar geographical regions.However, certain words or classes of words may be subject to manydifferent pronunciations, making accurate recognition and synthesis moredifficult. For example, proper names are often subject to differentpronunciations by different people, and it is often not possible todiscern the correct pronunciation based only on the spelling of thename. This ambiguity in the correct (or preferred) pronunciation ofnames is a possible source of recognition and synthesis errors by adigital assistant.

Accordingly, there is a need for systems and methods to allow users tospecify pronunciations of words for recognition and synthesis by adigital assistant.

SUMMARY

The implementations described herein allow users to specify a correct ora preferred pronunciation of words, such as proper names, so that adigital assistant can both recognize and synthesize the word based onthe specified pronunciation. (The term “correct” does not necessarilyrefer to a single, universally correct pronunciation, as severaldifferent pronunciations of a word may be considered “correct” byvarious individuals and/or in various dialects, accents, languages,etc.) For example, a user can speak a word or name to a digitalassistant, and the digital assistant will adjust its speech recognitionprocess to associate the specified pronunciation with the word, andadjust its speech synthesis process so that, when the word is spoken bythe digital assistant, it conforms to the user-specified pronunciation.In many cases, however, speech recognition and speech synthesis areperformed by different processes using different phoneticrepresentations of the word. Specifically, speech recognition phoneticalphabets are often different from speech synthesis phonetic alphabets,because the phonemes used to generate speech are typically differentfrom those used to recognize speech. More specifically, a speechrecognizer may not be able to (or may not need to) detect as manyphonemes as a speech synthesizer can produce. And though a digitalassistant can detect phonemes in a speech input in order to learn auser-specified pronunciation, those phonemes may not be suitable for useby a speech synthesizer. Accordingly, separate phonetic representationsof the word must be used for speech recognition and synthesis processes.

Some implementations described herein generate phonetic representationsfor both speech recognition and synthesis based on a single spokeninput. By using only a single spoken input to train speech recognitionand speech synthesis processes, the number of interactions necessary totrain the digital assistant can be reduced, making the digital assistantappear smarter and more human. Moreover, accepting a spoken inputinstead of requiring the user to type or otherwise select a textualphonetic representation in a phonetic alphabet allows a more human-likeinteraction with the digital assistant, thus enhancing the userexperience and potentially increasing the user's confidence in thecapabilities of the digital assistant.

Using a single speech input also offers several benefits over techniquesthat require a user to type in or otherwise select textual phoneticrepresentations of a word. For example, users may be unfamiliar with theparticular phonetic alphabet used to train the digital assistant. And ifthe textual phonetic representations are simplified so that users canuse a standard alphabet (e.g., the Latin alphabet) to provide a phoneticrepresentation, differences in accents may result in further confusionand lead to the selection of incorrect pronunciations. As a specificexample, for the name “Philippe,” a user may represent the firstsyllable as “fill” in an effort to teach the digital assistant thepreferred pronunciation. But even the word “fill” may be pronounceddifferently by different people (e.g., a person with a French accent mayunderstand “fill” to be pronounced similar to “feel”). Thus, attemptingto specify word pronunciations using textual inputs often fail to solve,and can even increase, pronunciation errors. Accordingly, accepting aspoken input of a word simplifies the process of teaching a digitalassistant how to recognize and synthesize a word, and increases theaccuracy of the teaching process.

Also described herein are techniques whereby a digital assistant detectswhen its assumption about a word or name pronunciation is incorrect, andengages in a conversation with the user to acquire the correctpronunciation. For example, if a user asks a digital assistant to “senda text message to Philippe” (pronouncing the name “fill-eep-ay”) thedigital assistant may not properly recognize the name, and may tell theuser that it doesn't understand the input. The user may then bypass thedigital assistant altogether and manually send a text message to acontact named Philippe. The digital assistant can detect that the usertook this action, infer that there was problem in its recognition of thename “Philippe,” and engage the user in a dialogue to acquire a correctpronunciation.

If the digital assistant correctly recognizes a word, though, it maystill mispronounce the name when it uses the name in a synthesizedspeech output. When this occurs, a user can indicate that the name wasmispronounced, such as by saying “you said that wrong,” prompting thedigital assistant to engage in a dialogue to acquire a correctpronunciation.

The implementations disclosed herein provide methods, systems, computerreadable storage medium and user interfaces for a digital assistant tocorrectly and conveniently acquire correct word pronunciations forspeech recognition and synthesis.

According to some implementations, a method is performed at anelectronic device with one or more processors and memory storing one ormore programs for execution by the one or more processors. A firstspeech input including at least one word is received. A first phoneticrepresentation of the at least one word is determined, the firstphonetic representation comprising a first set of phonemes selected froma speech recognition phonetic alphabet. The first set of phonemes ismapped to a second set of phonemes to generate a second phoneticrepresentation, where the second set of phonemes are selected from aspeech synthesis phonetic alphabet. The second phonetic representationis stored in association with a text string corresponding to the atleast one word.

In some implementations, the text string is a name in a contact listassociated with a user. In some implementations, the text string isinput by a user via a keyboard. In some implementations, the text stringis from a webpage displayed by the electronic device.

In some implementations, after updating the speech recognizer, a secondspeech input including the at least one word is received. A thirdphonetic representation of the at least one word is determined. It isdetermined that the at least one word corresponds to the text stringbased on a determination that the third phonetic representation issubstantially similar to the first phonetic representation.

According to some implementations, a method is performed at anelectronic device with one or more processors and memory storing one ormore programs for execution by the one or more processors. An error isdetected in a speech based interaction with a digital assistant. Inresponse to detecting the error, a speech input is received from a user,the speech input including a pronunciation of one or more words. Thepronunciation is stored in association with a text string correspondingto the one or more words.

According to some implementations, a method is performed at anelectronic device with one or more processors and memory storing one ormore programs for execution by the one or more processors. Auser-specified pronunciation of a first user's name is received from thefirst user. The pronunciation of the first user's name is stored inassociation with the first user's name and a unique identifier of thefirst user. It is detected that a second user has created a contact itemincluding the first user's name and the unique identifier of the firstuser. The user-specified pronunciation is used for one or both ofrecognizing the first user's name in speech inputs by the second user,and synthesizing the first user's name in speech outputs to the seconduser by the digital assistant.

In accordance with some implementations, an electronic device includes adisplay, a touch-sensitive surface, optionally one or more sensors todetect intensity of contacts with the touch-sensitive surface, one ormore processors, memory, and one or more programs; the one or moreprograms are stored in the memory and configured to be executed by theone or more processors and the one or more programs include instructionsfor performing the operations of any of the methods described above. Inaccordance with some implementations, a computer readable storage mediumhas stored therein instructions which when executed by an electronicdevice with a display, a touch-sensitive surface, and optionally one ormore sensors to detect intensity of contacts with the touch-sensitivesurface, cause the device to perform the operations of any of themethods referred described above. In accordance with someimplementations, an electronic device includes: a display, atouch-sensitive surface, and optionally one or more sensors to detectintensity of contacts with the touch-sensitive surface; and means forperforming the operations of any of the methods described above. Inaccordance with some implementations, an information processingapparatus, for use in an electronic device with a display and atouch-sensitive surface, optionally one or more sensors to detectintensity of contacts with the touch-sensitive surface, includes meansfor performing the operations of any of the methods described above.

The details of one or more implementations of the subject matterdescribed in this specification are set forth in the accompanyingdrawings and the description below. Other features, aspects, andadvantages of the subject matter will become apparent from thedescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an environment in which a digitalassistant operates in accordance with some implementations.

FIG. 2 is a block diagram illustrating a digital assistant client systemin accordance with some implementations.

FIG. 3A is a block diagram illustrating a digital assistant system or aserver portion thereof in accordance with some implementations.

FIG. 3B is a block diagram illustrating functions of the digitalassistant shown in FIG. 3A in accordance with some implementations.

FIG. 3C is a diagram of a portion of an ontology in accordance with someimplementations.

FIG. 4 illustrates a portion of a contact list item in accordance withsome implementations.

FIGS. 5A-7 are flow diagrams of an exemplary method implemented by adigital assistant for learning word pronunciations, in accordance withsome implementations.

Like reference numerals refer to corresponding parts throughout thedrawings.

DESCRIPTION OF IMPLEMENTATIONS

FIG. 1 is a block diagram of an operating environment 100 of a digitalassistant according to some implementations. The terms “digitalassistant,” “virtual assistant,” “intelligent automated assistant,” or“automatic digital assistant,” refer to any information processingsystem that interprets natural language input in spoken and/or textualform to infer user intent, and performs actions based on the inferreduser intent. For example, to act on a inferred user intent, the systemcan perform one or more of the following: identifying a task flow withsteps and parameters designed to accomplish the inferred user intent,inputting specific requirements from the inferred user intent into thetask flow; executing the task flow by invoking programs, methods,services, APIs, or the Like; and generating output responses to the userin an audible (e.g. speech) and/or visual form.

Specifically, a digital assistant is capable of accepting a user requestat least partially in the form of a natural language command, request,statement, narrative, and/or inquiry. Typically, the user request seekseither an informational answer or performance of a task by the digitalassistant. A satisfactory response to the user request is eitherprovision of the requested informational answer, performance of therequested task, or a combination of the two. For example, a user may askthe digital assistant a question, such as “Where am I right now?” Basedon the user's current location, the digital assistant may answer, “Youare in Central Park near the west gate.” The user may also request theperformance of a task, for example, “Please invite my friends to mygirlfriend's birthday party next week.” In response, the digitalassistant may acknowledge the request by saying “Yes, right away,” andthen send a suitable calendar invite on behalf of the user to each ofthe user' friends listed in the user's electronic address book. Duringperformance of a requested task, the digital assistant sometimesinteracts with the user in a continuous dialogue involving multipleexchanges of information over an extended period of time. There arenumerous other ways of interacting with a digital assistant to requestinformation or performance of various tasks. In addition to providingverbal responses and taking programmed actions, the digital assistantalso provides responses in other visual or audio forms, e.g., as text,alerts, music, videos, animations, etc.

An example of a digital assistant is described in Applicant's U.S.Utility application Ser. No. 12/987,982 for “Intelligent AutomatedAssistant,” filed Jan. 10, 2011, the entire disclosure of which isincorporated herein by reference.

As shown in FIG. 1, in some implementations, a digital assistant isimplemented according to a client-server model. The digital assistantincludes a client-side portion 102 a, 102 b (hereafter “DA client 102”)executed on a user device 104 a, 104 b, and a server-side portion 106(hereafter “DA server 106”) executed on a server system 108. The DAclient 102 communicates with the DA server 106 through one or morenetworks 110. The DA client 102 provides client-side functionalitiessuch as user-facing input and output processing and communications withthe DA-server 106. The DA server 106 provides server-sidefunctionalities for any number of DA-clients 102 each residing on arespective user device 104.

In some implementations, the DA server 106 includes a client-facing I/Ointerface 112, one or more processing modules 114, data and models 116,and an I/O interface to external services 118. The client-facing I/Ointerface facilitates the client-facing input and output processing forthe digital assistant server 106. The one or more processing modules 114utilize the data and models 116 to determine the user's intent based onnatural language input and perform task execution based on inferred userintent. In some implementations, the DA-server 106 communicates withexternal services 120 through the network(s) 110 for task completion orinformation acquisition. The I/O interface to external services 118facilitates such communications.

Examples of the user device 104 include, but are not limited to, ahandheld computer, a personal digital assistant (PDA), a tabletcomputer, a laptop computer, a desktop computer, a cellular telephone, asmart phone, an enhanced general packet radio service (EGPRS) mobilephone, a media player, a navigation device, a game console, atelevision, a remote control, or a combination of any two or more ofthese data processing devices or other data processing devices. Moredetails on the user device 104 are provided in reference to an exemplaryuser device 104 shown in FIG. 2.

Examples of the communication network(s) 110 include local area networks(“LAN”) and wide area networks (“WAN”), e.g., the Internet. Thecommunication network(s) 110 may be implemented using any known networkprotocol, including various wired or wireless protocols, such as e.g.,Ethernet, Universal Serial Bus (USB), FIREWIRE, Global System for MobileCommunications (GSM), Enhanced Data GSM Environment (EDGE), codedivision multiple access (CDMA), time division multiple access (TDMA),Bluetooth, Wi-Fi, voice over Internet Protocol (VoIP), Wi-MAX, or anyother suitable communication protocol.

The server system 108 is implemented on one or more standalone dataprocessing apparatus or a distributed network of computers. In someimplementations, the server system 108 also employs various virtualdevices and/or services of third party service providers (e.g.,third-party cloud service providers) to provide the underlying computingresources and/or infrastructure resources of the server system 108.

Although the digital assistant shown in FIG. 1 includes both aclient-side portion (e.g., the DA-client 102) and a server-side portion(e.g., the DA-server 106), in some implementations, the functions of adigital assistant is implemented as a standalone application installedon a user device. In addition, the divisions of functionalities betweenthe client and server portions of the digital assistant can vary indifferent implementations. For example, in some implementations, the DAclient is a thin-client that provides only user-facing input and outputprocessing functions, and delegates all other functionalities of thedigital assistant to a backend server.

FIG. 2 is a block diagram of a user-device 104 in accordance with someimplementations. The user device 104 includes a memory interface 202,one or more processors 204, and a peripherals interface 206. The variouscomponents in the user device 104 are coupled by one or morecommunication buses or signal lines. The user device 104 includesvarious sensors, subsystems, and peripheral devices that are coupled tothe peripherals interface 206. The sensors, subsystems, and peripheraldevices gather information and/or facilitate various functionalities ofthe user device 104.

For example, a motion sensor 210, a light sensor 212, and a proximitysensor 214 are coupled to the peripherals interface 206 to facilitateorientation, light, and proximity sensing functions. One or more othersensors 216, such as a positioning system (e.g., GPS receiver), atemperature sensor, a biometric sensor, a gyro, a compass, anaccelerometer, and the like, are also connected to the peripheralsinterface 206, to facilitate related functionalities.

In some implementations, a camera subsystem 220 and an optical sensor222 are utilized to facilitate camera functions, such as takingphotographs and recording video clips. Communication functions arefacilitated through one or more wired and/or wireless communicationsubsystems 224, which can include various communication ports, radiofrequency receivers and transmitters, and/or optical (e.g., infrared)receivers and transmitters. An audio subsystem 226 is coupled tospeakers 228 and a microphone 230 to facilitate voice-enabled functions,such as voice recognition, voice replication, digital recording, andtelephony functions.

In some implementations, an I/O subsystem 240 is also coupled to theperipheral interface 206. The I/O subsystem 240 includes a touch screencontroller 242 and/or other input controller(s) 244. The touch-screencontroller 242 is coupled to a touch screen 246. The touch screen 246and the touch screen controller 242 can, for example, detect contact andmovement or break thereof using any of a plurality of touch sensitivitytechnologies, such as capacitive, resistive, infrared, surface acousticwave technologies, proximity sensor arrays, and the like. The otherinput controller(s) 244 can be coupled to other input/control devices248, such as one or more buttons, rocker switches, thumb-wheel, infraredport, USB port, and/or a pointer device such as a stylus.

In some implementations, the memory interface 202 is coupled to memory250. The memory 250 can include high-speed random access memory and/ornon-volatile memory, such as one or more magnetic disk storage devices,one or more optical storage devices, and/or flash memory (e.g., NAND,NOR).

In some implementations, the memory 250 stores an operating system 252,a communication module 254, a user interface module 256, a sensorprocessing module 258, a phone module 260, and applications 262. Theoperating system 252 includes instructions for handling basic systemservices and for performing hardware dependent tasks. The communicationmodule 254 facilitates communicating with one or more additionaldevices, one or more computers and/or one or more servers. The userinterface module 256 facilitates graphic user interface processing andoutput processing using other output channels (e.g., speakers). Thesensor processing module 258 facilitates sensor-related processing andfunctions. The phone module 260 facilitates phone-related processes andfunctions. The application module 262 facilitates variousfunctionalities of user applications, such as electronic-messaging, webbrowsing, media processing, Navigation, imaging and/or other processesand functions.

As described in this specification, the memory 250 also storesclient-side digital assistant instructions (e.g., in a digital assistantclient module 264) and various user data 266 (e.g., user-specificvocabulary data, preference data, and/or other data such as the user'selectronic address book, to-do lists, shopping lists, user-specifiedname pronunciations, etc.) to provide the client-side functionalities ofthe digital assistant.

In various implementations, the digital assistant client module 264 iscapable of accepting voice input (e.g., speech input), text input, touchinput, and/or gestural input through various user interfaces (e.g., theI/O subsystem 244) of the user device 104. The digital assistant clientmodule 264 is also capable of providing output in audio (e.g., speechoutput), visual, and/or tactile forms. For example, output can beprovided as voice, sound, alerts, text messages, menus, graphics,videos, animations, vibrations, and/or combinations of two or more ofthe above. During operation, the digital assistant client module 264communicates with the digital assistant server using the communicationsubsystems 224.

In some implementations, the digital assistant client module 264includes a speech synthesis module 265. The speech synthesis module 265synthesizes speech outputs for presentation to the user. The speechsynthesis module 265 synthesizes speech outputs based on text providedby the digital assistant. For example, the digital assistant generatestext to provide as an output to a user, and the speech synthesis module265 converts the text to an audible speech output. The speech synthesismodule 265 uses any appropriate speech synthesis technique in order togenerate speech outputs from text, including but not limited toconcatenative synthesis, unit selection synthesis, diphone synthesis,domain-specific synthesis, formant synthesis, articulatory synthesis,hidden Markov model (HMM) based synthesis, and sinewave synthesis.

In some implementations, the speech synthesis module 265 storescanonical pronunciations for certain words. For example, the speechsynthesis module 265 may store a sequence of phonemes for the word “the”that is known to produce a correct pronunciation when synthesized. Insome implementations, multiple possible pronunciations are stored for agiven word, including user-specified pronunciations. As describedherein, the pronunciation that is ultimately selected for synthesis isdetermined based on any of several possible factors or combinationsthereof (e.g., the most common user-specified pronunciation, the mostcommon user-specified pronunciation in a geographical area, etc.).

In some implementations, where a user has provided a correct orpreferred pronunciation for a word (e.g., a proper name), the speechsynthesis module 265 uses the user-specified pronunciation for thosewords to the exclusion of other possible pronunciations. (Techniques foracquiring and processing user-specified pronunciations are discussedherein.) In some implementations, user-specified pronunciations for useby the speech synthesis module 265 are represented using a speechsynthesis phonetic alphabet (e.g., an alphabet or other symboliclinguistic representation used by the speech synthesis module 265 tosynthesize speech outputs).

In some implementations, the user-specified pronunciations are stored inthe user data 266. For example, user-specified pronunciations of thenames of contacts in a user's electronic address book or contact listare stored in association with the respective contacts. User-specifiedpronunciations may be visible or hidden to the user. When they arevisible and/or accessible to the user, they may be manually correctablethrough the electronic address book. For example, a user can select auser-specified pronunciation and modify, alter, or replace it, usingtext or speech inputs.

In some implementations, user-specified pronunciations of other words(e.g., words that are not names of a user's contacts) are stored inuser-specific vocabularies in the user data 266. Thus, in someimplementations, any words for which the user wishes to specify aparticular pronunciation are accessible by the speech synthesis module265.

In some implementations, user-specified pronunciations are storedremotely from the user device 104, such as in a remote server orcloud-based service (e.g., server system 108, FIG. 1). In such cases,the user-specified pronunciations are still associated with the user,and may be encrypted or otherwise secured so that only an authorizeduser and/or the authorized user's devices can access the information.Accordingly, user-specified pronunciations of words are accessible to auser via multiple user devices. This also helps increase the perceivedintelligence of the digital assistant, because once a user specifies aparticular pronunciation of a word or name, the digital assistant canuse the correct pronunciation regardless of whether the user isinteracting with the digital assistant on her smart phone or othercomputing device, e.g., laptop computer or tablet.

In some implementations, user-specified pronunciations are stored bothlocally (e.g., on one or more user devices 104) and remotely (e.g., onthe server system 108). In some implementations, user-specifiedpronunciations for a particular user are copied to a user device uponauthentication of the device to access an account associated with theuser. For example, user-specified pronunciations stored on the serversystem 108 may be associated with a particular user account, and when adevice becomes associated with that user account (e.g., because the userlogged into his or her account on that device), user data (e.g., userdata 266) for that account is sent to or otherwise becomes accessible bythe device.

In some implementations, instead of (or in addition to) using the localspeech synthesis module 265, speech synthesis is performed on a remotedevice (e.g., the server system 108), and the synthesized speech is sentto the user device 104 for output to the user. For example, this occursin some implementations where outputs for a digital assistant aregenerated at a server system. And because server systems generally havemore processing power or resources than a user device, it may bepossible to obtain higher quality speech outputs than would be practicalwith client-side synthesis.

In some implementations, the digital assistant client module 264utilizes the various sensors, subsystems and peripheral devices togather additional information from the surrounding environment of theuser device 104 to establish a context associated with a user, thecurrent user interaction, and/or the current user input. In someimplementations, the digital assistant client module 264 provides thecontext information or a subset thereof with the user input to thedigital assistant server to help infer the user's intent. In someimplementations, the digital assistant also uses the context informationto determine how to prepare and delivery outputs to the user.

In some implementations, the context information that accompanies theuser input includes sensor information, e.g., lighting, ambient noise,ambient temperature, images or videos of the surrounding environment,etc. In some implementations, the context information also includes thephysical state of the device, e.g., device orientation, device location,device temperature, power level, speed, acceleration, motion patterns,cellular signals strength, etc. In some implementations, informationrelated to the software state of the user device 106, e.g., runningprocesses, installed programs, past and present network activities,background services, error logs, resources usage, etc., of the userdevice 104 are provided to the digital assistant server as contextinformation associated with a user input.

In some implementations, the DA client module 264 selectively providesinformation (e.g., user data 266) stored on the user device 104 inresponse to requests from the digital assistant server. In someimplementations, the digital assistant client module 264 also elicitsadditional input from the user via a natural language dialogue or otheruser interfaces upon request by the digital assistant server 106. Thedigital assistant client module 264 passes the additional input to thedigital assistant server 106 to help the digital assistant server 106 inintent deduction and/or fulfillment of the user's intent expressed inthe user request.

In various implementations, the memory 250 includes additionalinstructions or fewer instructions. Furthermore, various functions ofthe user device 104 may be implemented in hardware and/or in firmware,including in one or more signal processing and/or application specificintegrated circuits.

FIG. 3A is a block diagram of an example digital assistant system 300 inaccordance with some implementations. In some implementations, thedigital assistant system 300 is implemented on a standalone computersystem. In some implementations, the digital assistant system 300 isdistributed across multiple computers. In some implementations, some ofthe modules and functions of the digital assistant are divided into aserver portion and a client portion, where the client portion resides ona user device (e.g., the user device 104) and communicates with theserver portion (e.g., the server system 108) through one or morenetworks, e.g., as shown in FIG. 1. In some implementations, the digitalassistant system 300 is an implementation of the server system 108(and/or the digital assistant server 106) shown in FIG. 1. It should benoted that the digital assistant system 300 is only one example of adigital assistant system, and that the digital assistant system 300 mayhave more or fewer components than shown, may combine two or morecomponents, or may have a different configuration or arrangement of thecomponents. The various components shown in FIG. 3A may be implementedin hardware, software instructions for execution by one or moreprocessors, firmware, including one or more signal processing and/orapplication specific integrated circuits, or a combination of thereof.

The digital assistant system 300 includes memory 302, one or moreprocessors 304, an input/output (I/O) interface 306, and a networkcommunications interface 308. These components communicate with oneanother over one or more communication buses or signal lines 310.

In some implementations, the memory 302 includes a non-transitorycomputer readable medium, such as high-speed random access memory and/ora non-volatile computer readable storage medium (e.g., one or moremagnetic disk storage devices, flash memory devices, or othernon-volatile solid-state memory devices).

In some implementations, the I/O interface 306 couples input/outputdevices 316 of the digital assistant system 300, such as displays,keyboards, touch screens, and microphones, to the user interface module322. The I/O interface 306, in conjunction with the user interfacemodule 322, receives user inputs (e.g., voice input, keyboard inputs,touch inputs, etc.) and processes them accordingly. In someimplementations, e.g., when the digital assistant is implemented on astandalone user device, the digital assistant system 300 includes any ofthe components and I/O and communication interfaces described withrespect to the user device 104 in FIG. 2. In some implementations, thedigital assistant system 300 represents the server portion of a digitalassistant implementation, and interacts with the user through aclient-side portion residing on a user device (e.g., the user device 104shown in FIG. 2).

In some implementations, the network communications interface 308includes wired communication port(s) 312 and/or wireless transmissionand reception circuitry 314. The wired communication port(s) receive andsend communication signals via one or more wired interfaces, e.g.,Ethernet, Universal Serial Bus (USB), FIREWIRE, etc. The wirelesscircuitry 314 receives and sends RF signals and/or optical signalsfrom/to communications networks and other communications devices. Thewireless communications may use any of a plurality of communicationsstandards, protocols and technologies, such as GSM, EDGE, CDMA, TDMA,Bluetooth, Wi-Fi, VoIP, Wi-MAX, or any other suitable communicationprotocol. The network communications interface 308 enables communicationbetween the digital assistant system 300 with networks, such as theInternet, an intranet and/or a wireless network, such as a cellulartelephone network, a wireless local area network (LAN) and/or ametropolitan area network (MAN), and other devices.

In some implementations, memory 302, or the computer readable storagemedia of memory 302, stores programs, modules, instructions, and datastructures including all or a subset of: an operating system 318, acommunications module 320, a user interface module 322, one or moreapplications 324, and a digital assistant module 326. The one or moreprocessors 304 execute these programs, modules, and instructions, andreads/writes from/to the data structures.

The operating system 318 (e.g., Darwin, RTXC, LINUX, UNIX, OS X,WINDOWS, or an embedded operating system such as VxWorks) includesvarious software components and/or drivers for controlling and managinggeneral system tasks (e.g., memory management, storage device control,power management, etc.) and facilitates communications between varioushardware, firmware, and software components.

The communications module 320 facilitates communications between thedigital assistant system 300 with other devices over the networkcommunications interface 308. For example, the communication module 320may communicate with the communication interface 254 of the device 104shown in FIG. 2. The communications module 320 also includes variouscomponents for handling data received by the wireless circuitry 314and/or wired communications port 312.

The user interface module 322 receives commands and/or inputs from auser via the I/O interface 306 (e.g., from a keyboard, touch screen,pointing device, controller, and/or microphone), and generates userinterface objects on a display. The user interface module 322 alsoprepares and delivers outputs (e.g., speech, sound, animation, text,icons, vibrations, haptic feedback, and light, etc.) to the user via theI/O interface 306 (e.g., through displays, audio channels, speakers, andtouch-pads, etc.).

The applications 324 include programs and/or modules that are configuredto be executed by the one or more processors 304. For example, if thedigital assistant system is implemented on a standalone user device, theapplications 324 may include user applications, such as games, acalendar application, a navigation application, or an email application.If the digital assistant system 300 is implemented on a server farm, theapplications 324 may include resource management applications,diagnostic applications, or scheduling applications, for example.

The memory 302 also stores the digital assistant module (or the serverportion of a digital assistant) 326. In some implementations, thedigital assistant module 326 includes the following sub-modules, or asubset or superset thereof: an input/output processing module 328, aspeech-to-text (STT) processing module 330, a phonetic alphabetconversion module 331, a natural language processing module 332, adialogue flow processing module 334, a task flow processing module 336,a service processing module 338, and a speech interaction errordetection module 339. Each of these modules has access to one or more ofthe following data and models of the digital assistant 326, or a subsetor superset thereof: ontology 360, vocabulary index 344, user data 348,task flow models 354, and service models 356.

In some implementations, using the processing modules, data, and modelsimplemented in the digital assistant module 326, the digital assistantperforms at least some of the following: identifying a user's intentexpressed in a natural language input received from the user; activelyeliciting and obtaining information needed to fully infer the user'sintent (e.g., by disambiguating words, names, intentions, etc.);determining the task flow for fulfilling the inferred intent; andexecuting the task flow to fulfill the inferred intent.

In some implementations, as shown in FIG. 3B, the I/O processing module328 interacts with the user through the I/O devices 316 in FIG. 3A orwith a user device (e.g., a user device 104 in FIG. 1) through thenetwork communications interface 308 in FIG. 3A to obtain user input(e.g., a speech input) and to provide responses (e.g., as speechoutputs) to the user input. The I/O processing module 328 optionallyobtains context information associated with the user input from the userdevice, along with or shortly after the receipt of the user input. Thecontext information includes user-specific data, vocabulary, and/orpreferences relevant to the user input. In some implementations, thecontext information also includes software and hardware states of thedevice (e.g., the user device 104 in FIG. 1) at the time the userrequest is received, and/or information related to the surroundingenvironment of the user at the time that the user request was received.In some implementations, the I/O processing module 328 also sendsfollow-up questions to, and receives answers from, the user regardingthe user request. When a user request is received by the I/O processingmodule 328 and the user request contains a speech input, the I/Oprocessing module 328 forwards the speech input to the speech-to-text(STT) processing module 330 for speech-to-text conversions.

The speech-to-text processing module 330 (or speech recognizer) receivesspeech input (e.g., a user utterance captured in a voice recording)through the I/O processing module 328. In some implementations, the STTprocessing module 330 uses various acoustic and language models torecognize the speech input as a sequence of phonemes, and ultimately, asequence of words or tokens written in one or more languages. The STTprocessing module 330 can be implemented using any suitable speechrecognition techniques, acoustic models, and language models, such asHidden Markov Models, Dynamic Time Warping (DTW)-based speechrecognition, and other statistical and/or analytical techniques. In someimplementations, the speech-to-text processing can be performed at leastpartially by a third party service or on the user's device. Once the STTprocessing module 330 obtains the result of the speech-to-textprocessing, e.g., a sequence of words or tokens, it passes the result tothe natural language processing module 332 for intent deduction. In someimplementations, the STT module 330 resides on a server computer (e.g.,the server system 108), while in some implementations, it resides on aclient device (e.g., the user device 104).

In some implementations, the STT processing module 330 includes and/oraccesses a vocabulary of recognizable words. Each word is associatedwith one or more candidate pronunciations of the word represented in aspeech recognition phonetic alphabet. For example, the vocabulary mayinclude the word “tomato” in association with the candidatepronunciations of “tuh-may-doe” and “tuh-mah-doe.” In someimplementations, the candidate pronunciations for words are determinedbased on the spelling of the word and one or more linguistic and/orphonetic rules. In some implementations, the candidate pronunciationsare manually generated, e.g., based on known canonical pronunciations.

In some implementations, the candidate pronunciations are ranked basedon the commonness of the candidate pronunciation. For example, thecandidate pronunciation “tuh-may-doe” may be ranked higher than“tuh-mah-doe,” because the former is a more commonly used pronunciationin the user's geographic region. In some implementations, one of thecandidate pronunciations is selected as a predicted pronunciation (e.g.,the most likely pronunciation).

When an utterance is received, the STT processing module 330 attempts toidentify the phonemes in the utterance (e.g., using an acoustic model),and then attempts to identify words that match the phonemes (e.g., usinga language model). For example, if the STT processing module 330 firstidentifies the sequence of phonemes “tuh-may-doe” in an utterance, itthen determines, based on the vocabulary 344, that this sequencecorresponds to the word “tomato.”

In some implementations, the STT processing module 330 uses approximatematching techniques to determine words in an utterance. Thus, forexample, the STT processing module 330 can determine that the sequenceof phonemes “duh-may-doe” corresponds to the word “tomato,” even if thatparticular sequence of phonemes is not one of the candidatepronunciations for that word.

As described herein, in some implementations, the STT processing module330 identifies phonemes in an utterance of a known word for the purposeof generating a user-specified pronunciation of the word. Thus, forexample, a user can add a user-specified pronunciation for the word“tomato” by simply speaking the preferred pronunciation to the digitalassistant. The STT processing module 330 processes the utterancecontaining the preferred pronunciation to identify the phonemes in theutterance. For example, the STT processing module 330 may identify thephonemes “tuh-may-duh” in the utterance, and store that set of phonemes(e.g., in the vocabulary index 344 and/or user data 348) as auser-specified pronunciation for the word “tomato.”

In some implementations, the speech-to-text processing module 330 usesuser-specified pronunciations to help recognize certain words in userutterances. For example, a user may discover that the digital assistantcannot accurately recognize a particular contact's name. By specifying apreferred pronunciation for the name, the digital assistant, andspecifically the speech-to-text processing module 330, will thereafteraccurately recognize the name in user utterances.

In some implementations, user-specified pronunciations for speechrecognition by the speech-to-text processing module 330 are stored inthe vocabulary index 344. In some implementations, user-specifiedpronunciations are also or instead stored in association with words inuser data 348. For example, if a user specifies a pronunciation for aname in her contact list (which is stored in user data 348), theuser-specified pronunciation is stored in association with the contactand/or the name in user data 348 or 266. In some implementations,user-specified name pronunciations are visible to the user, while inimplementations they are not.

In some implementations, all user-specified pronunciations are stored inuser data 348 or 266, and are accessed by the STT processing module 330and/or incorporated into the vocabulary index 344 when appropriate.Thus, user data for specific users is stored in association with a useraccount, and is used to augment and/or customize a generic STTprocessing module and/or vocabulary index, for example, when a userauthorizes a new device to access his account.

In some implementations, user-specified pronunciations for use by thespeech-to-text processing module 330 are represented using a speechrecognition phonetic alphabet (e.g., an alphabet or other symboliclinguistic representation used by the speech-to-text processing module330 to recognize speech inputs). In some implementations, the speechrecognition phonetic alphabet corresponds to the set of phonemes thatthe STT processing module 330 is capable of identifying in a recordingof a spoken utterance. In some implementations, the speech recognitionalphabet is the International Phonetic Alphabet (“IPA”), or a subset ofthe IPA that contains phonemes likely to be used by users in aparticular geographical region or by speakers of a particular language.

The phonetic alphabet conversion module 331 converts phoneticrepresentations of words between different phonetic alphabets.Specifically, in some implementations, a speech recognizer (e.g., theSTT processing module 330) uses a speech recognition phonetic alphabetto determine the phonemes in an utterance, while a speech synthesizer(e.g., the speech synthesis module 265, FIG. 2) uses a speech synthesisphonetic alphabet that is different from the speech recognition phoneticalphabet to synthesize a speech output. Speech synthesizers and speechrecognizers, therefore, cannot share a single phonetic representationbecause they use different phonetic alphabets. Thus, in someimplementations, the phonetic alphabet conversion module 331 convertsphonetic representations from one phonetic alphabet (e.g., a speechrecognition phonetic alphabet) into a second phonetic alphabet that isdifferent than the first (e.g., a speech synthesis phonetic alphabet).Accordingly, as described herein, a phonetic representation of a wordthat is determined using the STT processing module 330 can be convertedor mapped to a phonetic alphabet that is usable by the speech synthesismodule 265.

The natural language processing module 332 (“natural languageprocessor”) of the digital assistant takes the sequence of words ortokens (“token sequence”) generated by the speech-to-text processingmodule 330, and attempts to associate the token sequence with one ormore “actionable intents” recognized by the digital assistant. An“actionable intent” represents a task that can be performed by thedigital assistant, and has an associated task flow implemented in thetask flow models 354. The associated task flow is a series of programmedactions and steps that the digital assistant takes in order to performthe task. The scope of a digital assistant's capabilities is dependenton the number and variety of task flows that have been implemented andstored in the task flow models 354, or in other words, on the number andvariety of “actionable intents” that the digital assistant recognizes.The effectiveness of the digital assistant, however, is also dependenton the assistant's ability to infer the correct “actionable intent(s)”from the user request expressed in natural language.

In some implementations, in addition to the sequence of words or tokensobtained from the speech-to-text processing module 330, the naturallanguage processor 332 also receives context information associated withthe user request, e.g., from the I/O processing module 328. The naturallanguage processor 332 optionally uses the context information toclarify, supplement, and/or further define the information contained inthe token sequence received from the speech-to-text processing module330. The context information includes, for example, user preferences,hardware and/or software states of the user device, sensor informationcollected before, during, or shortly after the user request, priorinteractions (e.g., dialogue) between the digital assistant and theuser, and the like. As described in this specification, contextinformation is dynamic, and can change with time, location, content ofthe dialogue, and other factors.

In some implementations, the natural language processing is based one.g., ontology 360. The ontology 360 is a hierarchical structurecontaining many nodes, each node representing either an “actionableintent” or a “property” relevant to one or more of the “actionableintents” or other “properties”. As noted above, an “actionable intent”represents a task that the digital assistant is capable of performing,i.e., it is “actionable” or can be acted on. A “property” represents aparameter associated with an actionable intent or a sub-aspect ofanother property. A linkage between an actionable intent node and aproperty node in the ontology 360 defines how a parameter represented bythe property node pertains to the task represented by the actionableintent node.

In some implementations, the ontology 360 is made up of actionableintent nodes and property nodes. Within the ontology 360, eachactionable intent node is linked to one or more property nodes eitherdirectly or through one or more intermediate property nodes. Similarly,each property node is linked to one or more actionable intent nodeseither directly or through one or more intermediate property nodes. Forexample, as shown in FIG. 3C, the ontology 360 may include a “restaurantreservation” node (i.e., an actionable intent node). Property nodes“restaurant,” “date/time” (for the reservation), and “party size” areeach directly linked to the actionable intent node (i.e., the“restaurant reservation” node). In addition, property nodes “cuisine,”“price range,” “phone number,” and “location” are sub-nodes of theproperty node “restaurant,” and are each linked to the “restaurantreservation” node (i.e., the actionable intent node) through theintermediate property node “restaurant.” For another example, as shownin FIG. 3C, the ontology 360 may also include a “set reminder” node(i.e., another actionable intent node). Property nodes “date/time” (forthe setting the reminder) and “subject” (for the reminder) are eachlinked to the “set reminder” node. Since the property “date/time” isrelevant to both the task of making a restaurant reservation and thetask of setting a reminder, the property node “date/time” is linked toboth the “restaurant reservation” node and the “set reminder” node inthe ontology 360.

An actionable intent node, along with its linked concept nodes, may bedescribed as a “domain.” In the present discussion, each domain isassociated with a respective actionable intent, and refers to the groupof nodes (and the relationships therebetween) associated with theparticular actionable intent. For example, the ontology 360 shown inFIG. 3C includes an example of a restaurant reservation domain 362 andan example of a reminder domain 364 within the ontology 360. Therestaurant reservation domain includes the actionable intent node“restaurant reservation,” property nodes “restaurant,” “date/time,” and“party size,” and sub-property nodes “cuisine,” “price range,” “phonenumber,” and “location.” The reminder domain 364 includes the actionableintent node “set reminder,” and property nodes “subject” and“date/time.” In some implementations, the ontology 360 is made up ofmany domains. Each domain may share one or more property nodes with oneor more other domains. For example, the “date/time” property node may beassociated with many different domains (e.g., a scheduling domain, atravel reservation domain, a movie ticket domain, etc.), in addition tothe restaurant reservation domain 362 and the reminder domain 364.

While FIG. 3C illustrates two example domains within the ontology 360,other domains (or actionable intents) include, for example, “initiate aphone call,” “find directions,” “schedule a meeting,” “send a message,”and “provide an answer to a question,” “read a list”, “providingnavigation instructions,” “provide instructions for a task” and so on. A“send a message” domain is associated with a “send a message” actionableintent node, and may further include property nodes such as“recipient(s)”, “message type”, and “message body.” The property node“recipient” may be further defined, for example, by the sub-propertynodes such as “recipient name” and “message address.”

In some implementations, the ontology 360 includes all the domains (andhence actionable intents) that the digital assistant is capable ofunderstanding and acting upon. In some implementations, the ontology 360may be modified, such as by adding or removing entire domains or nodes,or by modifying relationships between the nodes within the ontology 360.

In some implementations, nodes associated with multiple relatedactionable intents may be clustered under a “super domain” in theontology 360. For example, a “travel” super-domain may include a clusterof property nodes and actionable intent nodes related to travels. Theactionable intent nodes related to travels may include “airlinereservation,” “hotel reservation,” “car rental,” “get directions,” “findpoints of interest,” and so on. The actionable intent nodes under thesame super domain (e.g., the “travels” super domain) may have manyproperty nodes in common. For example, the actionable intent nodes for“airline reservation,” “hotel reservation,” “car rental,” “getdirections,” “find points of interest” may share one or more of theproperty nodes “start location,” “destination,” “departure date/time,”“arrival date/time,” and “party size.”

In some implementations, each node in the ontology 360 is associatedwith a set of words and/or phrases that are relevant to the property oractionable intent represented by the node. The respective set of wordsand/or phrases associated with each node is the so-called “vocabulary”associated with the node. The respective set of words and/or phrasesassociated with each node can be stored in the vocabulary index 344 inassociation with the property or actionable intent represented by thenode. For example, returning to FIG. 3B, the vocabulary associated withthe node for the property of “restaurant” may include words such as“food,” “drinks,” “cuisine,” “hungry,” “eat,” “pizza,” “fast food,”“meal,” and so on. For another example, the vocabulary associated withthe node for the actionable intent of “initiate a phone call” mayinclude words and phrases such as “call,” “phone,” “dial,” “ring,” “callthis number,” “make a call to,” and so on. The vocabulary index 344optionally includes words and phrases in different languages.

The natural language processor 332 receives the token sequence (e.g., atext string) from the speech-to-text processing module 330, anddetermines what nodes are implicated by the words in the token sequence.In some implementations, if a word or phrase in the token sequence isfound to be associated with one or more nodes in the ontology 360 (viathe vocabulary index 344), the word or phrase will “trigger” or“activate” those nodes. Based on the quantity and/or relative importanceof the activated nodes, the natural language processor 332 will selectone of the actionable intents as the task that the user intended thedigital assistant to perform. In some implementations, the domain thathas the most “triggered” nodes is selected. In some implementations, thedomain having the highest confidence value (e.g., based on the relativeimportance of its various triggered nodes) is selected. In someimplementations, the domain is selected based on a combination of thenumber and the importance of the triggered nodes. In someimplementations, additional factors are considered in selecting the nodeas well, such as whether the digital assistant has previously correctlyinterpreted a similar request from a user.

In some implementations, the digital assistant also stores names ofspecific entities in the vocabulary index 344, so that when one of thesenames is detected in the user request, the natural language processor332 will be able to recognize that the name refers to a specificinstance of a property or sub-property in the ontology. In someimplementations, the names of specific entities are names of businesses,restaurants, people, movies, and the like. In some implementations, thedigital assistant searches and identifies specific entity names fromother data sources, such as the user's address book, a movies database,a musicians database, and/or a restaurant database. In someimplementations, when the natural language processor 332 identifies thata word in the token sequence i s a name of a specific entity (such as aname in the user's address book), that word is given additionalsignificance in selecting the actionable intent within the ontology forthe user request.

For example, when the words “Mr. Santo” are recognized from the userrequest, and the last name “Santo” is found in the vocabulary index 344as one of the contacts in the user's contact list, then it is likelythat the user request corresponds to a “send a message” or “initiate aphone call domain. For another example, when the words “ABC Café” arefound in the user request, and the term “ABC Café” is found in thevocabulary index 344 as the name of a particular restaurant in theuser's city, then it is likely that the user request corresponds to a“restaurant reservation” domain.

User data 348 includes user-specific information, such as user-specificvocabulary, user preferences, user address, user's default and secondarylanguages, user's contact list, and other short-term or long-terminformation for each user. In some implementations, the natural languageprocessor 332 uses the user-specific information to supplement theinformation contained in the user input to further define the userintent. For example, for a user request “invite my friends to mybirthday party,” the natural language processor 332 is able to accessuser data 348 to determine who the “friends” are and when and where the“birthday party” would be held, rather than requiring the user toprovide such information explicitly in his/her request.

Other details of searching an ontology based on a token string isdescribed in U.S. Utility application Ser. No. 12/341,743 for “Methodand Apparatus for Searching Using An Active Ontology,” filed Dec. 22,2008, the entire disclosure of which is incorporated herein byreference.

In some implementations, once the natural language processor 332identifies an actionable intent (or domain) based on the user request,the natural language processor 332 generates a structured query torepresent the identified actionable intent. In some implementations, thestructured query includes parameters for one or more nodes within thedomain for the actionable intent, and at least some of the parametersare populated with the specific information and requirements specifiedin the user request. For example, the user may say “Make me a dinnerreservation at a sushi place at 7.” In this case, the natural languageprocessor 332 may be able to correctly identify the actionable intent tobe “restaurant reservation” based on the user input. According to theontology, a structured query for a “restaurant reservation” domain mayinclude parameters such as {Cuisine}, {Time}, {Date}, {Party Size}, andthe like. In some implementations, based on the information contained inthe user's utterance, the natural language processor 332 generates apartial structured query for the restaurant reservation domain, wherethe partial structured query includes the parameters {Cuisine=“Sushi”}and {Time=“7 pm”}. However, in this example, the user's utterancecontains insufficient information to complete the structured queryassociated with the domain. Therefore, other necessary parameters suchas {Party Size} and {Date} are not specified in the structured querybased on the information currently available. In some implementations,the natural language processor 332 populates some parameters of thestructured query with received context information. For example, in someimplementations, if the user requested a sushi restaurant “near me,” thenatural language processor 332 populates a {location} parameter in thestructured query with GPS coordinates from the user device 104.

In some implementations, the natural language processor 332 passes thestructured query (including any completed parameters) to the task flowprocessing module 336 (“task flow processor”). The task flow processor336 is configured to receive the structured query from the naturallanguage processor 332, complete the structured query, if necessary, andperform the actions required to “complete” the user's ultimate request.In some implementations, the various procedures necessary to completethese tasks are provided in task flow models 354. In someimplementations, the task flow models include procedures for obtainingadditional information from the user, and task flows for performingactions associated with the actionable intent.

As described above, in order to complete a structured query, the taskflow processor 336 may need to initiate additional dialogue with theuser in order to obtain additional information, and/or disambiguatepotentially ambiguous utterances. When such interactions are necessary,the task flow processor 336 invokes the dialogue processing module 334(“dialogue processor 334”) to engage in a dialogue with the user. Insome implementations, the dialogue processor 334 determines how (and/orwhen) to ask the user for the additional information, and receives andprocesses the user responses. The questions are provided to and answersare received from the users through the I/O processing module 328. Insome implementations, the dialogue processor 334 presents dialogueoutput to the user via audio and/or visual output, and receives inputfrom the user via spoken or physical (e.g., clicking) responses.Continuing with the example above, when the task flow processor 336invokes the dialogue flow processor 334 to determine the “party size”and “date” information for the structured query associated with thedomain “restaurant reservation,” the dialogue flow processor 335generates questions such as “For how many people?” and “On which day?”to pass to the user. Once answers are received from the user, thedialogue flow processor 334 can then populate the structured query withthe missing information, or pass the information to the task flowprocessor 336 to complete the missing information from the structuredquery.

In some cases, the task flow processor 336 may receive a structuredquery that has one or more ambiguous properties. For example, astructured query for the “send a message” domain may indicate that theintended recipient is “Bob,” and the user may have multiple contactsnamed “Bob.” The task flow processor 336 will request that the dialogueprocessor 334 disambiguate this property of the structured query. Inturn, the dialogue processor 334 may ask the user “Which Bob?”, anddisplay (or read) a list of contacts named “Bob” from which the user maychoose.

Once the task flow processor 336 has completed the structured query foran actionable intent, the task flow processor 336 proceeds to performthe ultimate task associated with the actionable intent. Accordingly,the task flow processor 336 executes the steps and instructions in thetask flow model according to the specific parameters contained in thestructured query. For example, the task flow model for the actionableintent of “restaurant reservation” may include steps and instructionsfor contacting a restaurant and actually requesting a reservation for aparticular party size at a particular time. For example, using astructured query such as: {restaurant reservation, restaurant=ABC Café,date=Mar. 12, 2012, time=7 pm, party size=5}, the task flow processor336 may perform the steps of: (1) logging onto a server of the ABC Caféor a restaurant reservation system such as OPENTABLE®, (2) entering thedate, time, and party size information in a form on the website, (3)submitting the form, and (4) making a calendar entry for the reservationin the user's calendar.

In some implementations, the task flow processor 336 employs theassistance of a service processing module 338 (“service processor”) tocomplete a task requested in the user input or to provide aninformational answer requested in the user input. For example, theservice processor 338 can act on behalf of the task flow processor 336to make a phone call, set a calendar entry, invoke a map search, invokeor interact with other user applications installed on the user device,and invoke or interact with third party services (e.g. a restaurantreservation portal, a social networking website, a banking portal,etc.). In some implementations, the protocols and applicationprogramming interfaces (API) required by each service can be specifiedby a respective service model among the services models 356. The serviceprocessor 338 accesses the appropriate service model for a service andgenerates requests for the service in accordance with the protocols andAPIs required by the service according to the service model.

For example, if a restaurant has enabled an online reservation service,the restaurant can submit a service model specifying the necessaryparameters for making a reservation and the APIs for communicating thevalues of the necessary parameter to the online reservation service.When requested by the task flow processor 336, the service processor 338can establish a network connection with the online reservation serviceusing the web address stored in the service model, and send thenecessary parameters of the reservation (e.g., time, date, party size)to the online reservation interface in a format according to the API ofthe online reservation service.

In some implementations, the natural language processor 332, dialogueprocessor 334, and task flow processor 336 are used collectively anditeratively to infer and define the user's intent, obtain information tofurther clarify and refine the user intent, and finally generate aresponse (i.e., an output to the user, or the completion of a task) tofulfill the user's intent.

In some implementations, after all of the tasks needed to fulfill theuser's request have been performed, the digital assistant 326 formulatesa confirmation response, and sends the response back to the user throughthe I/O processing module 328. If the user request seeks aninformational answer, the confirmation response presents the requestedinformation to the user. In some implementations, the digital assistantalso requests the user to indicate whether the user is satisfied withthe response produced by the digital assistant 326.

The error detection module 339 detects errors in interactions between auser and the digital assistant. In some implementations, to detecterrors, the error detection module 339 monitors interactions between auser and the digital assistant, and/or between a user and a user device.For example, the error detection module 339 monitors any of thefollowing types of interactions, or a subset thereof: a user's speechinputs to the digital assistant (e.g., if a user says “you got thatwrong” or “you are pronouncing that wrong”), button presses (e.g., if auser selects a lock-screen or “home” button (or any other affordance) tocancel an action), movements of the device (e.g., shaking the device,setting the device down in a certain orientation, such as screen-down),termination of actions or suggested actions on the user device (e.g.,cancelling a telephone call, email, text message, etc. after the digitalassistant initiates or suggests it), initiation of an action shortlyafter a digital assistant fails to successfully infer an intent oradequately respond to a user, etc. In some implementations, the errordetection module 339 monitors other types of interactions to detecterrors as well.

In order to detect such errors, in some implementations, the errordetection module 339 communicates with or otherwise receives informationfrom various modules and components of the digital assistant system 300and/or the user device 104, such as the I/O processing module 328(and/or the I/O devices 316), the STT processing module 330, naturallanguage processing module 332, the dialogue flow processing module 334,the task flow processing module 336, the service processing module 338,the phone module 260, the sensor processing module 258, the I/Osubsystem 240, and/or any of the sensors or I/O devices associatedtherewith.

In some implementations, the error detection module 339 monitors actionstaken by the user on the user device 104 after the user cancels anaction and/or dialogue with the digital assistant prior to thecompletion of the action or dialogue. In particular, actions taken bythe user after such an occurrence often indicate both that the digitalassistant did not accurately infer the user's intent (or did notunderstand the user's speech input), and what the digital assistantshould have done based on the user's input. As a specific example, auser may ask the digital assistant to “Call Philippe,” and the digitalassistant may respond by saying “Calling Phil.” The user may quicklycancel the telephone call to Phil, exit the dialogue with the digitalassistant, and proceed to manually initiate a telephone call with acontact named Philippe. Accordingly, the error detection module 339detects that because the telephone call to Phil was canceled, an errorwas made, and that the speech input to call “Philippe” should beassociated with the contact that was manually selected by the user.

More details on the digital assistant can be found in the U.S. Utilityapplication Ser. No. 12/987,982, entitled “Intelligent AutomatedAssistant”, filed Jan. 10, 2011, U.S. Utility Application No.61/493,201, entitled “Generating and Processing Data Items ThatRepresent Tasks to Perform”, filed Jun. 3, 2011, the entire disclosuresof which are incorporated herein by reference.

In most scenarios, when the digital assistant receives a user input froma user, the digital assistant attempts to provide an appropriateresponse to the user input with as little delay as possible. Forexample, suppose the user requests certain information (e.g., currenttraffic information) by providing a speech input (e.g., “How does thetraffic Look right now?”). Right after the digital assistant receivesand processes the speech input, the digital assistant optionallyprovides a speech output (e.g., “Looking up traffic information . . . ”)acknowledging receipt of the user request. After the digital assistantobtains the requested information in response to the user request, thedigital assistant proceeds to provide the requested information to theuser without further delay. For example, in response to the user'straffic information request, the digital assistant may provide a seriesof one or more discrete speech outputs separated by brief pauses (e.g.,“There are 2 accidents on the road. <Pause> One accident is on 101 northbound near Whipple Avenue. <Pause> And a second accident is on 85 northnear 280.”), immediately after the speech outputs are generated.

For the purpose of this specification, the initial acknowledgement ofthe user request and the series of one or more discrete speech outputsprovided in response to the user request are all consideredsub-responses of a complete response to the user request. In otherwords, the digital assistant initiates an information provision processfor the user request upon receipt of the user request, and during theinformation provision process, the digital assistant prepares andprovides each sub-response of the complete response to the user requestwithout requiring further prompts from the user.

Sometimes, additional information or clarification (e.g., routeinformation) is required before the requested information can beobtained. In such scenarios, the digital assistant outputs a question(e.g., “Where are you going?”) to the user asking for the additionalinformation or clarification. In some implementations, the questionprovided by the digital assistant is considered a complete response tothe user request because the digital assistant will not take furtheractions or provide any additional response to the user request until anew input is received from the user. In some implementations, once theuser provides the additional information or clarification, the digitalassistant initiates a new information provision process for a “new” userrequest established based on the original user request and theadditional user input.

In some implementations, the digital assistant initiates a newinformation provision process upon receipt of each new user input, andeach existing information provision process terminates either (1) whenall of the sub-responses of a complete response to the user request havebeen provided to the user or (2) when the digital assistant provides arequest for additional information or clarification to the userregarding a previous user request that started the existing informationprovision process.

In general, after a user request for information or performance of atask is received by the digital assistant, it is desirable that thedigital assistant provides a response (e.g., either an output containingthe requested information, an acknowledgement of a requested task, or anoutput to request a clarification) as promptly as possible. Real-timeresponsiveness of the digital assistant is one of the key factors inevaluating performance of the digital assistant. In such cases, aresponse is prepared as quickly as possible, and a default delivery timefor the response is a time immediately after the response is prepared.

Sometimes, however, after an initial sub-response provided immediatelyafter receipt of the user input, the digital assistant provides theremaining one or more sub-responses one at a time over an extendedperiod of time. In some implementations, the information provisionprocess for a user request is stretched out over an extended period oftime that is longer than the sum of the time required to provide eachsub-response individually. For example, in some implementations, shortpauses (i.e., brief periods of silence) are inserted between an adjacentpair of sub-responses (e.g., a pair of consecutive speech outputs) whenthey are delivered to the user through an audio-output channel.

In some implementations, a sub-response is held in abeyance after it isprepared and is delivered only when a predetermined condition has beenmet. In some implementations, the predetermined condition is met when apredetermined trigger time has been reached according to a system clockand/or when a predetermined trigger event has occurred. For example, ifthe user says to the digital assistant “set me a timer for 5 minutes,”the digital assistant initiates an information provision process uponreceipt of the user request. During the information provision process,the digital assistant provides a first sub-response (e.g., “OK, timerstarted.”) right away, and does not provide a second and finalsub-response (e.g., “OK, five minutes are up”) until 5 minutes later. Insuch cases, the default delivery time for the first sub-response is atime immediately after the first sub-response is prepared, and thedefault delivery time for the second, final sub-response is a timeimmediately after the occurrence of the trigger event (e.g., the elapseof 5 minutes from the start of the timer). The information provisionprocess is terminated when the digital assistant finishes providing thefinal sub-response to the user. In various implementations, the secondsub-response is prepared any time (e.g., right after the firstsub-response is prepared, or until shortly before the default deliverytime for the second sub-response) before the default delivery time forthe second sub-response.

FIG. 4 illustrates a portion of a contact list entry 400, according tosome implementations. The contact list entry 400 includes auser-specified pronunciation for a name and a standard pronunciation forthe name, each stored in association with the name. While FIG. 4 depictsa contact list entry, the figure and associated description appliesequally to words from other lists, databases, vocabularies, etc., suchas the vocabulary index 344. In some implementations, the contact listentry 400 is stored in user data 348 or 266.

The contact list entry 400 includes a name 402 (“Philippe”). The contactlist entry 400 also includes a user-specified pronunciation for thename. The user-specified pronunciations for this name may be obtainedand/or generated as described elsewhere in this application. Because, insome implementations, the STT processing module 330 and the speechsynthesis module 265 use different phonetic alphabets, theuser-specified pronunciation includes a phonetic representation of thename 402 in a speech recognition alphabet (phonetic representation 404),as well as a phonetic representation of the name 402 in a speechsynthesis alphabet (phonetic representation 406). Both therepresentation 404 in the recognition alphabet and the representation406 in the synthesis alphabet are based on the same pronunciation, and,therefore, the user's preferred pronunciation will both be accuratelyrecognized by the STT processing module 330 and accurately synthesizedby the speech synthesis module 265.

The phonetic representations in FIG. 4 are used herein merely toillustrate that, although they represent the same pronunciation,phonetic representations for recognition and synthesis are differentfrom one another, and that the phonemes are selected from differentphonetic alphabets and/or sets of phonemes. The particular phoneticrepresentations in FIG. 4 do not necessarily reflect any particularphonetic alphabet, any particular phonemes for use by speechsynthesizers or recognizers, nor any particular phoneme sequences thatmay be associated with the word shown. Rather, they are intended to helpillustrate the differences between different pronunciations (e.g.,standard and user-specified pronunciations) and between phonemesequences for speech recognition and speech synthesis.

The contact list entry 400 also includes a standard pronunciationincluding a phonetic representation of the name 402 in a speechrecognition alphabet (phonetic representation 408), as well as aphonetic representation of the name 402 in a speech synthesis alphabet(phonetic representation 410). The standard pronunciation represents adefault pronunciation for recognition and synthesis that is used by thedigital assistant absent any user-specified pronunciations for thatword. In some implementations, the digital assistant maintains thestandard pronunciation in addition to any user-specified pronunciations.

In some implementations, contact list entries (or any word in thevocabulary 344 and/or user data 348) include more or less informationthan depicted in FIG. 4. Moreover, the user-specified pronunciation andthe standard pronunciation (and their respective recognition andsynthesis phonetic representations) need not be stored in a commonlocation or device. For example, in some implementations, the speechrecognition phonetic representations 404 and 408 are stored on a server(e.g., the server system 108) in association with a STT processingmodule (e.g., the STT processing module 330), while the speech synthesisphonetic representations 406 and 410 are stored on a user device (e.g.,user device 104) in association with a speech synthesis module (e.g.,the speech synthesis module 265). In some implementations, all of thephonetic representations are stored on a both a server and a userdevice. In some implementations, the speech recognition phoneticrepresentations 404 and 408 and the speech synthesis phoneticrepresentations 406 and 410 are stored in any appropriate combination oneither or both of a server and a user device.

Furthermore, in some implementations, user-specified pronunciations arestored in association with a user's contacts (or other user-specificdata), while standard pronunciations are not stored in association withthe user, but are part of the generic STT processing and speechsynthesis modules used by multiple different instances of a digitalassistant.

FIGS. 5A-5B are flow diagrams of an exemplary method 500 implemented bya digital assistant for learning word pronunciations. In someimplementations, the method 500 is performed at an electronic devicewith one or more processors and memory storing one or more programs forexecution by the one or more processors. For example, in someimplementations, the method 500 is performed at the user device 104and/or the server system 108. In some implementations, the method 500 isperformed by the digital assistant system 300 (FIG. 3A), which, as notedabove, may be implemented on a standalone computer system (e.g., eitherthe user device 104 or the server system 108) or distributed acrossmultiple computers (e.g., the user device 104, the server system 108,and/or additional or alternative devices or systems). While thefollowing discussion describes the method 500 as being performed by adigital assistant (e.g., the digital assistant system 300), the methodis not limited to performance by any particular device or combination ofdevices. Moreover, the individual steps of the method may be distributedamong the one or more computers, systems, or devices in any appropriatemanner.

The digital assistant receives a first speech input including at leastone word (502). In some implementations, the speech input corresponds toa user utterance recorded and/or received by the user device 104. Insome implementations, the first input is received in the course of aninteraction with the digital assistant. In some implementations, theword is a name, such as a name of a contact associated with a user. As aspecific example, the utterance may be “Call Philippe Martin,”corresponding to a request by the user to initiate a telephone call witha contact named Philippe Martin. In some implementations, the firstinput is received during an interaction in which the user isspecifically training the digital assistant how to pronounce aparticular word. As a specific example, the utterance may be “Pleasepronounce that ‘Philippe,’” or, if the digital assistant has alreadyprompted the user to provide a preferred pronunciation for a particularword, the utterance may simply be “Philippe.”

The digital assistant determines a first phonetic representation of theat least one word (504), the first phonetic representation comprising afirst set of phonemes selected from a speech recognition phoneticalphabet. In some implementations, the first phonetic representation ofthe at least one word is determined by a speech-to-text processor (e.g.,the STT processing module 330, FIG. 3A). The speech recognition phoneticalphabet is an alphabet or other symbolic linguistic representation usedby the speech-to-text processor to recognize speech inputs. For example,in some implementations, the speech recognition phonetic alphabet is theInternational Phonetic Alphabet.

In some implementations, the speech-to-text processor determines thefirst phonetic representation by processing the speech input using anacoustic model to determine the phonemes in the utterance. For example,the set of phonemes for the word “Philippe” in above example above maybe represented as “f-ill-ee-p-ay.”

The digital assistant maps the first set of phonemes to a second set ofphonemes to generate a second phonetic representation (e.g., with thephonetic alphabet conversion module 331, FIG. 3A), wherein the secondset of phonemes are selected from a speech synthesis phonetic alphabet(506). In some implementations, the speech recognition phonetic alphabetis different than the speech synthesis phonetic alphabet. For example,the first set of phonemes in the speech recognition alphabet“f-ill-ee-p-ay” may be converted to the second set of phonemes“fill-eep-ay.” By converting the first set of phonemes in a speechrecognition alphabet to a speech synthesis alphabet, the pronunciationof the one or more words that were actually used by the user is capableof being used by both the speech recognizer and the speech synthesizerof the digital assistant, i.e., to recognize spoken words and tosynthesize speech output.

In some implementations, the digital assistant includes conversiontables, maps, or equivalency lists to convert phonetic representationsbetween different phonetic alphabets. Exemplary systems and methods forconverting words and/or phonetic representations from one alphabet toanother are described in Applicant's U.S. Utility application Ser. No.13/469,047 for “Generalized Phonetic Transliteration Engine,” filed May10, 2012, the entire disclosure of which is incorporated herein byreference. In some implementations, the mapping includes using aweighted finite state transducer to map the first set of phonemes to thesecond set of phonemes. In some implementations, the mapping includesusing a statistical model to map the first set of phonemes to the secondset of phonemes.

The digital assistant stores the second phonetic representation inassociation with a text string corresponding to the at least one word(508). For example, the second phonetic representation “fill-eep-ay” isstored in a contact list in association with a contact having the name“Philippe” (e.g., as a user-specified pronunciation for a name in acontact list of a user). In some implementations, the second phoneticrepresentation is stored in the user data 348 and/or the vocabularyindex 344.

In some implementations, prior to receiving the first speech input, thetext string is provided (501). In some implementations, the text stringis a name in a contact list associated with a user. In someimplementations, the name in the contact list is selected by a user,such as by navigating to a contact list application and selecting a namein the contact list for which to supply a preferred pronunciation. Insome implementations, the text string is input by a user via a keyboard.For example, the user may type one or more words into a device (e.g.,the user device 104) and then provide the first speech input (step 502)to specify a preferred pronunciation for one or more of the typed words.As another example, the user can select a contact (e.g., by pressing andholding a contact item in a contact list) and concurrently speak thepreferred pronunciation for the name of the contact.

In some implementations, the text string is from a webpage displayed byan electronic device. For example, a user can select a word in a webpage(e.g., by touching, pressing, or clicking on the word), and then providea speech input such as “pronounce this word as [word].”

Rather than requiring the user to manually identify the text string, thedigital assistant may identify the text string automatically. In someimplementations, the digital assistant determines the text string usingthe first phonetic representation (505). This may be accomplished bydetermining that the utterance corresponds to a certain sequence ofletters, even if the digital assistant does not recognize that sequenceof letters as a word. For example, a speech recognizer can determinethat the phonemes “tuh-may-doe” correspond to the letters “t o m a t o,”even if that word is not in the speech recognizer's vocabulary. In someimplementations, the digital assistant uses fuzzy matching and/orapproximate matching techniques to determine the text string from thefirst phonetic representation. For example, if a user provides a speechinput to a digital assistant asking to call “f-ill-ee-p-ay,” but thisparticular phonetic sequence has not been associated with the name“Philippe,” the digital assistant uses fuzzy matching to determine that“f-ill-ee-p-ay” is sufficiently close to the sequence “f-ill-ee-p,”which is a candidate pronunciation for the name Philippe. Thus, thedigital assistant determines that the text string “Philippe” correspondsto the word in the utterance, even though the user's pronunciation ofthat word was not one of the candidate pronunciations.

In some implementations, the digital assistant updates a speechrecognizer (e.g., the STT processing module 330) to associate the firstphonetic representation with the text string (510). In someimplementations, the first phonetic representation is stored as acandidate phonetic representation for the text string, for example, in auser-specific speech recognition vocabulary (e.g., the vocabulary index344), or in a contact item in a contact list or address book (e.g., inthe user data 348).

By associating the first phonetic representation of the word with thetext string, the speech recognizer is able to identify the word whenthat particular pronunciation is used. For example, in someimplementations, after updating the speech recognizer, the digitalassistant receives a second speech input including the at least one word(512). In some implementations, the second speech input is any inputreceived after the first input that includes the word. The digitalassistant determines a third phonetic representation of the at Least oneword (514) (e.g., using the STT processing module 330), and determinesthat the at Least one word corresponds to the text string based on adetermination that the third phonetic representation is substantiallysimilar to the first phonetic representation (516). Thus, the firstphonetic representation reflecting the user's preferred pronunciation ofa word is used to detect the word in later utterances.

Turning to FIG. 5B, by storing the second phonetic representation (forspeech synthesis) in association with the text string, the digitalassistant is able to use the user-specified pronunciation in speechoutputs that include the word. For example, in some implementations,after storing the second phonetic representation in association with thetext string, the digital assistant synthesizes a speech outputcorresponding to the text string using the second phoneticrepresentation (518). Accordingly, the synthesized speech output willsound substantially similar to the word in the speech input (e.g., theword as spoken by the user). As a specific example, after storing asecond phonetic representation “fill-eep-ay” (corresponding to theuser-specified pronunciation of the word in a speech synthesis phoneticalphabet), the digital assistant synthesizes a speech output using theuser-specified pronunciation of the word “Philippe” (e.g., “Okay, I'mplacing a telephone call to fill-eep-ay.”)

In some implementations, the digital assistant stores a plurality ofadditional first phonetic representations in association with the textstring (520), wherein the plurality of additional first phoneticrepresentations includes the first phonetic representation. For example,the plurality of additional first phonetic representations may be thecandidate phonetic representations described above. In particular, thefirst phonetic representation and a number of other candidate phoneticrepresentations may be stored in association with the text string foruse by a speech recognizer (e.g., the STT processing module 330) whenidentifying words in speech inputs. In some implementations, thecandidate representations are specific to a particular user (e.g., theyare stored in association with a particular user and/or useridentifier), while in some implementations, they are not specific to anyparticular user (e.g., they are part of a generic vocabulary for use bymultiple digital assistants and/or STT processors). By storing aplurality of first representations, the digital assistant provides morerobust recognition functionality, because it will successfullyrecognizer more pronunciations of the word.

In some implementations, the digital assistant selects a predictedphonetic representation for the text string from the plurality ofadditional first phonetic representations (522). A predicted phoneticrepresentation is one that is selected by the digital assistant as themost probable pronunciation for that word. In some implementations, thepredicted phonetic representation is a user-specified pronunciation. Insome implementations, the predicted phonetic representation is a genericor global pronunciation for that word. In some implementations, all ofthe phonetic representations of the plurality of additional firstphonetic representations are ranked in order of their likelihood of use,and the predicted phonetic representation ranked the highest.

In some implementations, where the candidate phonetic representations(including one or more user-specified pronunciations) are included in orare part of a generic vocabulary used by a plurality of digitalassistants, the predicted phonetic representation is selected in foreach user in accordance with a selection metric. In someimplementations, the predicted phonetic representation is a mostfrequently detected phonetic representation.

In some implementations, the predicted phonetic representation is themost frequently detected phonetic representation for a particularregion. For example, many users of digital assistants in a given regionmay specify the same pronunciation for the same word. Thus, the digitalassistant (e.g., a digital assistant server or other centralized systemthat communicates with or otherwise interacts with many digitalassistant clients) can determine the pronunciation that is mostfrequently specified by users in various geographical areas. Once apredicted phonetic representation is selected, it can be used for bothspeech recognition as well as speech synthesis (e.g., so that thedigital assistant will recognize that pronunciation in speech inputs, aswell as produce that pronunciation in speech outputs). The geographicalregion may be any appropriate geographical region(s), defined by anyappropriate geographical, geopolitical, or cultural boundaries. Forexample, the predicted pronunciation for the word “tomato” may be“tuh-may-doe” for users in the Western portion of the United States, and“tuh-mah-doe” for users in the Eastern portion of the United States.

While the above discussion relates to selecting a predicted phoneticrepresentation from a plurality of first representations (e.g., phoneticrepresentations in a speech recognition phonetic alphabet), thediscussion applies equally to selecting from among phoneticrepresentations in any phonetic alphabet (e.g., phonetic representationsin a speech synthesis phonetic alphabet).

FIG. 6 is a flow diagram of an exemplary method 600 implemented by adigital assistant for learning word pronunciations. In someimplementations, the method 600 is performed at an electronic devicewith one or more processors and memory storing one or more programs forexecution by the one or more processors. For example, in someimplementations, the method 600 is performed at the user device 104 orthe server system 108. In some implementations, the method 600 isperformed by the digital assistant system 300 (FIG. 3A), which, as notedabove, may be implemented on a standalone computer system (e.g., eitherthe user device 104 or the server system 108) or distributed acrossmultiple computers (e.g., the user device 104, the server system 108,and/or additional or alternative devices or systems). While thefollowing discussion describes the method 600 as being performed by adigital assistant (e.g., the digital assistant system 300), the methodis not limited to performance by any particular device or combination ofdevices. Moreover, the individual steps of the method may be distributedamong the one or more computers, systems, or devices in any appropriatemanner.

The method 600 relates to detecting errors in speech based interactionsin order to determine that the digital assistant should requestuser-specified pronunciations for one or more words. Various types oferrors may arise in speech based interactions. For example, errors inspeech recognition can prevent the digital assistant from accuratelyinferring the user's intent. Specifically, a STT processor might selectthe wrong word based on a speech input (e.g., detecting the word“potato” when the user actually said “tomato”), or might simply fail toidentify a suitable word for a portion of a text string (e.g., failingto transcribe a last name of a contact). Moreover, the digital assistantmight mispronounce a word (such as a contact name) during a speechinteraction, which can confuse the user. This is especially problematicwhen the digital assistant is used in an “eyes-free” mode, where theuser cannot simply read a text version of the speech output on a displayscreen to determine whether the digital assistant has identified thewrong name, or simply mispronounced a correctly identified name. Forexample, while driving, a user may say to a digital assistant “CallPhilippe,” and the digital assistant responds by saying “Calling[fill-up].” Upon hearing the mispronounced name, the user may not trustthat the digital assistant is placing a call to the correct person, andmay unnecessarily cancel the telephone call. Accordingly, when an erroris detected, it is often possible for the digital assistant to inferthat the error was likely caused by either an inability to recognize auser's pronunciation of a word, or an incorrect pronunciation in aspeech output by the digital assistant. In some implementations, errorsare detected automatically by the digital assistant (e.g., based oncertain patterns of use or interactions with the digital assistant or auser device that are indicative of an error), or are manually indicatedby a user (e.g., when a user provides a speech input that indicates anerror, or selects an affordance indicating that an error has occurred).Various specific ways of detecting errors are described herein.

Returning to the method 600, the digital assistant detects an error in aspeech based interaction with a digital assistant (608). In someimplementations, the error is an error in speech recognition of one ormore words that were received in a speech input provided by the user. Insome implementations, the error is an error in speech synthesis of oneor more words that were output in a speech output by the electronicdevice (e.g., a mispronunciation of one or more words). Specificexamples of errors in speech recognition and synthesis, and how they aredetected, are provided below.

In response to detecting the error, the digital assistant receives aspeech input from a user, the speech input including a pronunciation ofone or more words (612). In some implementations, prior to receiving thespeech input from the user, the digital assistant prompts the user toprovide a speech input including a preferred pronunciation afterdetecting an error (610). For example, in some implementations, afterdetecting an error in recognizing the name “Philippe,” the digitalassistant will display or say “I'm sorry I didn't understand you justnow—can you please tell me how you pronounce “Philippe” that so I canremember it?” The user can then speak the word to the digital assistant.

In some implementations, when the digital assistant prompts the user toprovide a pronunciation of one or more words, the digital assistant onlyrequests a pronunciation of one word at a time, so as to avoid detectingor incorporating erroneous phonemes from other words in the utterance.Specifically, if the user provides a speech input such as “pleasepronounce that as ‘Philippe’ from now on,” the speech recognizer mayhave difficulty parsing what syllables should be associated with thename “Philippe.”

In some implementations, when user-specified pronunciations arerequested for more than one word (e.g., a first name and a last name ofa contact item), the digital assistant provides separate prompts, andreceives separate inputs, for each name. Specifically, the digitalassistant may say “How shall I pronounce ‘Philippe’?” After receiving aresponse, the digital assistant may then say “Thanks. How shall Ipronounce ‘Martin’?”

In some implementations, the digital assistant determines a firstphonetic representation of the one or more words (614), the firstphonetic representation comprising a first set of phonemes selected froma speech recognition phonetic alphabet. In some implementations, thefirst phonetic representation of the at least one word is determined bya speech-to-text processor (e.g., the STT processing module 330, FIG.3A).

In some implementations, the digital assistant maps the first set ofphonemes to a second set of phonemes to generate a second phoneticrepresentation (e.g., with the phonetic alphabet conversion module 331,FIG. 3A), wherein the second set of phonemes are selected from a speechsynthesis phonetic alphabet (616). In some implementations, the speechrecognition phonetic alphabet is different than the speech synthesisphonetic alphabet. Mapping phonemes from one phonetic alphabet toanother is discussed in greater detail with respect to step (506) inFIG. 5A, above.

The digital assistant stores the pronunciation (including either or bothof the first phonetic representation and the second phoneticrepresentation) in association with a text string corresponding to theone or more words (614). In some implementations, receiving and storingthe pronunciation in association with the text string includesperforming one or more of the steps of the method 500, described above.

One type of error that the digital assistant detects is a low confidencein the recognition of a word in a speech input. Thus, in someimplementations, the digital assistant receives (prior to detecting theerror at step (608)) a speech input including one or more words (602).The digital assistant performs speech recognition on the speech input(e.g., with the STT processing module 330) to generate a text stringcorresponding to the one or more words (604). The digital assistantdetermines a confidence metric of the text string (606). In someimplementations, the confidence metric reflects how closely the phonemeset generated for a particular word (e.g., by the STT processing module330) corresponds to one or more of the candidate phoneme sets for thatword. The digital assistant then detects the error (608) based on adetermination that the confidence metric does not meet a predeterminedthreshold.

The digital assistant can also detect errors in speech synthesis, suchas pronunciation errors made by the digital assistant in a synthesizedspeech output. In some implementations, the digital assistantsynthesizes (prior to detecting the error at step (608)) a speech outputincluding one or more words (607). For example, the speech output may beused to indicate to the user what action the digital assistant is takingin response to a request from the user, such as when the digitalassistant says “Calling Philippe Martin” in response to a request toinitiate a phone call to that person. The digital assistant then detectsthe error (608) based on an indication from the user that the one ormore words were pronounced incorrectly by the digital assistant. In someimplementations, the indication from the user is a speech input wherethe user indicates that the digital assistant's pronunciation wasincorrect, such as “You said that name wrong” or “That's pronounced[f-ill-ee-p-ay].” In some implementations, the indication is a selectionof an affordance to cancel a telephone call that was initiated by thedigital assistant.

In some implementations, the digital assistant detects the error (608)based on detecting a user selection of the affordance. An affordancethat a user can select to indicate an error may be displayed to the userduring interactions with the digital assistant. For example, in someimplementations, when providing a synthesized speech output, the digitalassistant also displays a textual version of the speech output to theuser on a display. This may be helpful, for example, so that if a wordis mispronounced by the digital assistant, the user can simply refer tothe displayed text of the output to determine what the digital assistantwas trying to speak. In some implementations, the digital assistantprovides the affordance (e.g., a touchscreen button, a physical button,etc.) along with the displayed text so that the user can indicate that aspeech output includes a mispronounced word. In some implementations,the affordance is labeled “Did I mispronounce something?” or “Click hereto correct pronunciation mistakes.”

In some implementations, the digital assistant also determinesconfidence values for speech synthesis, and determines whether a speechoutput is likely to be misunderstood by a user and/or be likely to causea user to correct the digital assistant's pronunciation. In particular,speech synthesizers may be very confident that it will correctlypronounce common words and/or words that are in a vocabulary of known(e.g., pre-recorded) pronunciations. For example, speech synthesizerswill be very confident that it will correctly pronounce the words “call”and “the” and “sure,” among a multitude of possible examples. However,for words that are not in the vocabulary or for which no user-specifiedpronunciation has been provided, the digital assistant can identify thatits pronunciation of those words are more likely to be incorrect.Accordingly, in some implementations, the digital assistant determinesconfidence values for words in speech synthesis outputs. The digitalassistant can then monitor user interactions with the digital assistantand/or a user device to infer whether the pronunciation was correct ornot. For example, if the digital assistant receives an input such as“what was that?” after synthesizing one or more words with a lowpronunciation confidence value, the digital assistant responds (eitherimmediately or at a later time) with a response that better informs theuser of the intended word (either by spelling it or displaying it),requests correction by the user, or both. For example, the digitalassistant may provide an output such as “Sorry, I may have said thatwrong. Here's what I was trying to say p-h-i-l-i-p-p-e. Can you tell mehow to pronounce that?” Providing a speech output that spells the wordhaving a low confidence score is also beneficial when the digitalassistant is being used in an eyes-free mode, where the user cannot (orshould not) look at a display to read text. In particular, the user caneasily and quickly understand what the digital assistant was trying tosay, and the dialogue between the user and the digital assistant cancontinue once the pronunciation error is resolved (or dismissed by theuser).

In some implementations, when an error is detected in a speech output(e.g., by detecting a user interaction indicative of a mistake aftersynthesizing a word with a low pronunciation confidence level, asdescribed above), the digital assistant does not immediately prompt theuser to provide a correct pronunciation, but instead spells the word forthe user and attempts to continue to take appropriate actions to satisfythe user's intent. For example, if, after synthesizing the phrase“Calling Philippe Martin,” the digital assistant receives an input suchas “who?”, the digital assistant may respond by saying “Sorry, I musthave mispronounced that. Would you like me to call [philippe] Martin?”In some implementations, after the user's intent is satisfied (or if theuser dismisses or cancels the action), the digital assistant willrequest that the user provide a user-specified pronunciation for theword that it believes to have been mispronounced.

FIG. 7 is a flow diagram of an exemplary method 700 implemented by adigital assistant for learning word pronunciations. In someimplementations, the method 700 is performed at an electronic devicewith one or more processors and memory storing one or more programs forexecution by the one or more processors. For example, in someimplementations, the method 700 is performed at the user device 104 (ora plurality of user devices) or the server system 108. In someimplementations, the method 700 is performed by the digital assistantsystem 300 (FIG. 3A), which, as noted above, may be implemented on astandalone computer system (e.g., either the user device 104 or theserver system 108) or distributed across multiple computers (e.g., theuser device 104, the server system 108, and/or additional or alternativedevices or systems). While the following discussion describes the method700 as being performed by a digital assistant (e.g., the digitalassistant system 300), the method is not limited to performance by anyparticular device or combination of devices. Moreover, the individualsteps of the method may be distributed among the one or more computers,systems, or devices in any appropriate manner.

In accordance with some implementations, the method 700 allows apronunciation specified by one user to be used by other users for bothspeech recognition and synthesis. For example, once a user of a digitalassistant and/or a digital assistant service specifies how his or herown name is pronounced, that pronunciation can be provided to otherusers' digital assistants and/or devices (with appropriate permissionsby the first user) so that those digital assistants will recognize andpronounce the name correctly. In some implementations, a user's own namepronunciation is only shared if the user specifically authorizes it.

In some implementations, a user-specified pronunciation for a firstuser's name is shared with a second user (subject to authorization) whenthe second user creates a contact item (e.g., in a contact list oraddress book) for the first user. The contact item may be provided tothe second user by the first user directly (e.g., by sharing anelectronic business card or contact file), or may be manually created bythe second user (e.g., when the second user types in a name, phonenumber, or email address, etc., of the user into a contact list oraddress book on the second user's device).

Returning to FIG. 7 and method 700, the digital assistant receives froma first user, a user-specified pronunciation of the first user's name(702). The digital assistant stores the pronunciation of the firstuser's name in association with the first user's name and a uniqueidentifier of the first user (704). In some implementations, the firstuser's name is a textual representation of the first user's name. Insome implementations, the unique identifier is an email address of thefirst user. In some implementations, the unique identifier is atelephone number of the first user.

In some implementations, the first user's name and the unique identifierof the first user are stored in an electronic business card. In someimplementations, the electronic business card is in a vCard format.

In some implementations, the pronunciation, the name (e.g., a textualrepresentation of the name), and the unique identifier are stored on adevice associated with the first user (e.g., the user device 104). Insome implementations, the pronunciation, the name, and the uniqueidentifier are stored on a central server system associated with digitalassistants of a plurality of users (e.g., the server system 108). Insome implementations, the pronunciation, the name, and the uniqueidentifier are stored on a central server system and on the user devicesof one or more individual users (including, for example, the first userand other users authorized by the first user to access thepronunciation, as discussed below).

The digital assistant detects that a second user has created a contactitem including the first user's name and the unique identifier of thefirst user (706). The digital assistant uses the user-specifiedpronunciation for one or both of recognizing the first user's name inspeech inputs by the second user, and synthesizing the first user's namein speech outputs to the second user by the digital assistant (708).

In some implementations, when the second user creates and/or stores anew contact item, the second user's device communicates with the serversystem to determine if the user identified by the contact item isassociated with a user-specified pronunciation, and, if so, whether thesecond user is authorized to access it. In some implementations, if thesecond user is not authorized to access the user-specifiedpronunciation, an authorization request is provided to the first user toauthorize the second user to receive and/or access the user-specifiedpronunciation. In some implementations, the second user is not madeaware that it is accessing a user-specified pronunciation of the firstuser's name. Thus, once the second user's digital assistant gains accessto the user-specified pronunciation, it can be adopted and used by thesecond user's digital assistant, making it more accurate and making itappear even more intelligent and useful.

While the method 700 is described above for user-specifiedpronunciations of names, the method also applies to other words as well.For example, a first user may specify a pronunciation of a businessname, city, street name, or the like. These user-specifiedpronunciations can then be used by other users' digital assistants(subject to authorization) to correctly recognize and pronounce thesewords in speech inputs and outputs.

The operations described above with reference to FIGS. 5A-7 are,optionally, implemented by components depicted in FIG. 2 and/or FIG. 3.Similarly, it would be clear to a person having ordinary skill in theart how other processes can be implemented based on the componentsdepicted in FIG. 2 and/or FIG. 3.

It should be understood that the particular order in which theoperations have been described above is merely exemplary and is notintended to indicate that the described order is the only order in whichthe operations could be performed. One of ordinary skill in the artwould recognize various ways to reorder the operations described herein.

The foregoing description, for purpose of explanation, has beendescribed with reference to specific implementations. However, theillustrative discussions above are not intended to be exhaustive or tolimit the invention to the precise forms disclosed. Many modificationsand variations are possible in view of the above teachings. Theimplementations were chosen and described in order to best explain theprinciples of the invention and its practical applications, to therebyenable others skilled in the art to best utilize the invention andvarious implementations with various modifications as are suited to theparticular use contemplated.

What is claimed is:
 1. A method for learning word pronunciations,comprising: at an electronic device with one or more processors andmemory storing one or more programs for execution by the one or moreprocessors: receiving a first speech input including at least one word;determining a first phonetic representation of the at least one word,the first phonetic representation comprising a first set of phonemesselected from a speech recognition phonetic alphabet; mapping the firstset of phonemes to a second set of phonemes to generate a secondphonetic representation, the second set of phonemes selected from aspeech synthesis phonetic alphabet that is different from the speechrecognition phonetic alphabet, wherein the speech recognition phoneticalphabet and the speech synthesis phonetic alphabet are phoneticalphabets of a same language; and storing the second phoneticrepresentation in association with a text string corresponding to the atleast one word.
 2. The method of claim 1, further comprising, prior toreceiving the first speech input, providing the text string.
 3. Themethod of claim 2, wherein the text string is a name in a contact listassociated with a user.
 4. The method of claim 2, wherein the textstring is input by a user via a keyboard.
 5. The method of claim 2,wherein the text string is from a webpage displayed by the electronicdevice.
 6. The method of claim 1, further comprising determining thetext string using the first phonetic representation.
 7. The method ofclaim 1, further comprising updating a speech recognizer to associatethe first phonetic representation with the text string.
 8. The method ofclaim 7, further comprising: after updating the speech recognizer,receiving a second speech input including the at least one word;determining a third phonetic representation of the at least one word;and determining that the at least one word corresponds to the textstring based on a determination that the third phonetic representationis substantially similar to the first phonetic representation.
 9. Themethod of claim 1, further comprising, after storing the second phoneticrepresentation in association with the text string, synthesizing aspeech output corresponding to the text string using the second phoneticrepresentation.
 10. A non-transitory computer readable storage mediumstoring one or more programs, the one or more programs comprisinginstructions, which when executed by an electronic device with adisplay, cause the device to perform: receiving a first speech inputincluding at least one word; determining a first phonetic representationof the at least one word, the first phonetic representation comprising afirst set of phonemes selected from a speech recognition phoneticalphabet; mapping the first set of phonemes to a second set of phonemesto generate a second phonetic representation, the second set of phonemesselected from a speech synthesis phonetic alphabet that is differentfrom the speech recognition phonetic alphabet, wherein the speechrecognition phonetic alphabet and the speech synthesis phonetic alphabetare phonetic alphabets of a same language; and storing the secondphonetic representation in association with a text string correspondingto the at least one word.
 11. The computer readable storage medium ofclaim 10, further comprising instructions for causing the device toperform, prior to receiving the first speech input, providing the textstring.
 12. The computer readable storage medium of claim 11, whereinthe text string is a name in a contact list associated with a user. 13.The computer readable storage medium of claim 11, wherein the textstring is input by a user via a keyboard.
 14. The computer readablestorage medium of claim 11, wherein the text string is from a webpagedisplayed by the electronic device.
 15. The computer readable storagemedium of claim 10, further comprising instructions for causing theprocessor to perform determining the text string using the firstphonetic representation.
 16. The computer readable storage medium ofclaim 10, further comprising instructions for causing the processor toperform updating a speech recognizer to associate the first phoneticrepresentation with the text string.
 17. An electronic device,comprising: one or more processors; memory; and one or more programs,wherein the one or more programs are stored in the memory and configuredto be executed by the one or more processors, the one or more programsincluding instructions for performing: receiving a first speech inputincluding at least one word; determining a first phonetic representationof the at least one word, the first phonetic representation comprising afirst set of phonemes selected from a speech recognition phoneticalphabet; mapping the first set of phonemes to a second set of phonemesto generate a second phonetic representation, the second set of phonemesselected from a speech synthesis phonetic alphabet that is differentfrom the speech recognition phonetic alphabet, wherein the speechrecognition phonetic alphabet and the speech synthesis phonetic alphabetare phonetic alphabets of a same language; and storing the secondphonetic representation in association with a text string correspondingto the at least one word.
 18. The device of claim 17, further comprisinginstructions for performing, prior to receiving the first speech input,providing the text string.
 19. The device of claim 18, wherein the textstring is a name in a contact list associated with a user.
 20. Thedevice of claim 18, wherein the text string is input by a user via akeyboard.
 21. The device of claim 18, wherein the text string is from awebpage displayed by the electronic device.
 22. The device of claim 17,further comprising instructions for performing determining the textstring using the first phonetic representation.
 23. The device of claim17, further comprising instructions for performing updating a speechrecognizer to associate the first phonetic representation with the textstring.